CVE-2022-21656 X.509 subjectAltName matching bypass in Envoy

2022-02-2222:25:11

CWE-295

GitHub_M

www.cve.org

envoy

x.509

subjectaltname

bypass

nameconstraints

openssl

boringssl

CVSS3

7.4

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

NONE

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

0.001

Percentile

35.2%

JSON

Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a “type confusion” bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.

CNA Affected

[
  {
    "product": "envoy",
    "vendor": "envoyproxy",
    "versions": [
      {
        "status": "affected",
        "version": "< 1.20.2"
      }
    ]
  }
]